8: Sparse Matrices
( \newcommand{\kernel}{\mathrm{null}\,}\)
A sparse matrix is a matrix in which most of the entries are zero. Such matrices are very commonly encountered in finite-difference equations. For example, when we discretized the 1D Schrödinger wave equation with Dirichlet boundary conditions, we saw that the Hamiltonian matrix had the tridiagonal form
Hence, if there are